Sharing Calibration Settings: Results Compared
By Chris Heinonen on
Often when I write a review of a display or projector, someone asks me for my specific display settings. I typically mention which color temperature or picture mode works best, but many readers want specifics. How did I adjust the white balance controls? Did I make changes to the color management system? What about a 10-point white balance control?
I’ve always refused to give these specifics. Just like any product, there will be variations between two samples of the same display. I have no way to know if my settings will help or hurt a display, and most readers have no way to know if this will help them or not. Sharing calibration settings, and if it helps or hurts, is one area I’ve wanted to look into for a long time.
I just purchased a Panasonic VT60 plasma display, as did Ray Coronado, a calibrator in the Southern California area. Ray wanted to try to measure the results of using publicly available calibration settings on the VT60 with our individual units, and I wanted to know as well. We decided to take settings from two of the most used sources: D-Nice, a professional calibrator who has posted his data for years, and CNet, where they also post their settings.
For these measurements we made sure to break-in our displays for 100 hours using the slides that D-Nice provides. For all measurements we use 2% windows except for CNet as they use 18% windows for their calibrations and measurements.
I used an i1Pro and C6 while Ray used an i1Pro2 for readings. We also both measured against the default THX modes in our displays for reference points. We chose a gamma target of 2.2 as that is what CNet and THX both use, and what it seems that D-Nice also uses. The exception is for the THX Bright Room setting that seems to target a gamma of 1.9.
Here are my results first for all three copied settings and the two preset numbers.
|D-Nice Day||D-Nice Night||CNet||THX Cinema||THX BrightRoom|
|Light Output||43.3 fL||33.6 fL||38.6 fL||32.2 fL||53.9 fL|
|Color Checker dE2000||1.85||2.71||1.31||1.75||1.88|
What stands out here is that the best overall settings are possibly from CNet. The gamma is a little off, but the overall errors are lower than any other setting. It also uses the Cinema mode as a preset instead of using the Professional1 or Professional2 modes that D-Nice does. Once we look at these in more detail later you’ll see why I would never actually use the settings from CNet on my display.
Looking at the THX preset versus the D-Nice settings there is a lower Grayscale dE2000 from D-Nice, but higher color errors. Those are worse in the nighttime setting, which is more directly comparable to the THX Cinema setting than the Day mode is. The errors in THX Bright Room mode are overall very low. I think the gamma is too low, but the preset is very good overall.
Now we can look at the results that Ray has from his VT60.
|D-Nice Day||D-Nice Night||CNet||THX Cinema||THX BrightRoom|
|Light Output||40.7 fL||31.6 fL||36.6 fL||32.0 fL||50.6 fL|
|Color Checker dE2000||2.41||2.67||1.51||1.58||1.81|
Ray has higher error levels than I do with the D-Nice Day settings; though his night results are very close to mine. He has a better gamma with the CNet numbers, and we both have similar results from THX.
Two things stand out when I compare these. The first is that the light output from the settings is off by 5-10% between the two sets. Even with two sets of the same model, bought the same day from the same store, the light output can vary by this much with the same setting. We also see that copying the calibration settings from D-Nice gives us decent results, but not ones that are any better than the THX Cinema mode. They also vary a lot between the two displays. Now we want to look at these in more depth, to see some of the other differences between the two.
One note here: Ray used his i1Pro2 to measure everything so the 5% and 10% readings are only so reliable. It does not affect the overall results, as every preset is subject to the same issue, but if you notice a gamma dip at 5% or 10% the reason is more likely the instrument being used and not the display.
The best RGB Balance of any setting is the CNet settings on my display. The THX Cinema is good on both but leans to a bit too much red. On Ray’s set the CNet settings lean towards too little red more than mine do. On both sets the D-Nice settings have too little red in the RGB Balance. So perhaps the set, or sets, that D-Nice used to get these settings has more red in it by default than our sets do. So by copying his settings we are introducing even more red into the grayscale.
CNet did not use the 10-point gamma control to adjust their settings, so their gamma uses the defaults. It is a bit low for both of us, with dips at 5% and 90% for both of us. Overall the D-Nice gamma settings track quite well to the 2.2 target that he is after. The THX Bright Room setting tracks very close to 1.9 for both of us, with the same bump and dip on both sets. Both sets see a dip at 5% with THX Cinema mode, but otherwise good tracking for a target of 2.2. Once again I do not worry about the 5% readings here for Ray as that’s an i1Pro2 issue. You can see that the THX Bright Room mode tracks better because it has a lower gamma. This lets the i1Pro2 read the 5% sample better resulting in a flatter gamma.
When we look at the dE2000 error levels for the grayscale overall, we see they are almost invisible errors. A couple of points might pop up above the magic level of 3.0 but mostly they are well below it. The THX settings do just as well as copied calibrated settings here. For Ray, the THX error levels are better overall than the ones he achieved using the copied calibration settings. If you are hoping to improve the grayscale quality by copying settings instead of using the display defaults, you really aren’t going to get any benefit.
As mentioned earlier, the CNet grayscale quality is very high. It uses the Cinema mode instead of the Professional1 or Professional2 modes that D-Nice uses. Entering their settings they left the color settings alone except for an adjustment to the magenta. It seems that there is something different with their sample compared to ours, as you will see in the saturations charts below. Sample variations like this is a reason that many people do not like to share their settings. It is impossible to know if this flaw is specific to your set, or to the product.
Overall for the saturations we found that the THX modes were more accurate than copying settings, with the THX Bright Room mode being really accurate. D-Nice’s settings still gave us a result where more errors were below a dE2000 of 3.0, but higher than the THX Mode. The CNet settings are good except they have a huge flaw in magenta. There is no reason to use copied settings over the THX defaults here.
We also tested with the large Color Checker chart included in CalMAN 5.2. This tests a large number of samples that are not primary or secondary colors, but instead colors you find in the real world. Sky blues, natural greens, skin tones, and more. This is a more accurate test of the color management system in the display as many can get primary and secondary colors right, but fail when it comes time to do colors between those points.
With these results it looks like the CNet numbers are the best, except for Magenta which causes a few large errors. These errors are well past the visible error limit, so they will show up. The difference between a dE2000 of 1.0 and 2.5 is typically not visible, while the one between 2.5 and 7.0 will be visible. As low as the overall errors are for the CNet settings, those few colors having large errors makes it the worst choice to me.
Looking at the D-Nice settings they are low overall errors, except they are still worse than the THX modes. The work of inputting these settings isn’t adding any benefit to the display and is adding a level of randomness that might not exist with the THX mode.
One interesting note is that on Ray’s THX Cinema mode, one skin tone kept registering an error level over 19.0 for him. He measured it five times and still got the same result. He didn’t notice the error in real world watching, so we tend to think it is a software glitch over the display being so far incorrect here. However we are not certain of this. If this reading is wrong, than his overall Color Checker dE2000 error level would fall by 0.15-0.18.
As we have seen, copying calibration settings did not do anything to improve upon the THX modes that are inside the VT60. With sample variations, what settings might work for someone will not necessarily work for another person. Both Ray and I achieved slightly different results with the same settings and a TV set ordered from the same company on the same day. On a set made earlier in the year, perhaps those settings worked better but we do not know.
After doing these measurements I calibrated my VT60 in Professional1 mode for myself. Unlike the preset modes, I want a gamma of 2.4 so I have darker shadow detail when I watch without any ambient light. Otherwise I used the same targets that I did earlier.
As you can see the overall error levels are incredibly low. None of the issues seen when using copied settings are present and there are no visible flaws in this image. With a full 6-point CMS that offers Hue, Saturation and Color adjustments, as well as a 10-point white balance and gamma controls, the VT60 offers the controls you need to hit your reference targets. This is an improvement over the standard THX settings and how I will run my display at night when it is totally dark.
What do I take away from this? We only have a pair of displays available to us to test, so this is a very small sample. In our cases, copying settings does not improve upon the THX modes. For almost everyone those THX modes are accurate enough that they will be very happy to use them and never want anything more. If you want a more accurate image you can get one but only by calibrating that individual display. Just copying the adjustments someone else made to the same model will not make yours better.
Now when asked why I don’t share my calibration settings, I will simply point back to this article. Compared to the pre-calibrated settings from the factory mine are not likely to improve the set and will probably only make it worse. If you really want the most accurate set you can get, then you’ll need to have it individually calibrated as every display is unique.
how many hours do you have on the panel now? i know at 200 hours i had to re-do a complete calibration
Chris Heinonen says
We each made sure to have over 100 hours on the panel. I can do another set of measurements in another 200 hours to see if there is any difference in THX modes and my calibrated mode compared to now but there shouldn’t be a large drift. Projectors will show a drift but plasma typically does not.
Chris, thanks for the valuable information. I support your conclusions completely. However, as Ray noted, you may want to evaluate further with a few more hours on the sets. As D-Nice, Kevin, et al said at the VE shootout that the Panasonic plasma sets weren’t quite settled down until after 300 hours of break-in.
Chris Heinonen says
It had just over 110 hours when I calibrated, which falls in line with how long D-Nice recommends running his slides for, and close to how long CNet would break in a set before viewing it. Most reviewers don’t spend that long to break in a set and most owners probably don’t as well. I can certainly take a second set of measurements to see how well they do at 300 hours, though. I don’t expect much change, if any.
I understand regarding the 100 hour mark but all 3 of the calibrators at the VE Shootout noted that the 2013 Panasonics required much more break in time than what is typically required. They said things stabilized past the 300 hour mark.
Smith Clarkson says
i need to make the re-do complete calibration at 120 ours, your’s is quite impressive
Helson Rodriguez says
Hi, my name is Helson Rodriguez and I am an ISF II Certified Calibrator here In Puerto Rico. I’m new to this web site, so here is my two cents. That is why I always do a 300 hour break-in to all my Plasma clients, and 100 hour break-in to my LCD and LCD-LED clients. I personally own an LG Plasma and have witnessed that the 300 hour mark seem to be the right number. I use a i1Pro for profiling and a Klein K-10 and I have seen drifting even at the 250-275 hours mark. Chris very informative, keep up the great work!
Chris Heinonen says
I will try to measure this again closer to the 300 hour mark. The 100 hour mark is what is suggested by people for using break-in slides before entering someone else’s settings so we went with that. I’ll also measure my own calibration at 300 hours to see if it has drifted much at all. I usually recommend 200-300 hours for someone before I adjust their set as well.
I’m envious of the K-10, one of those is on my wish list.
Helson Rodriguez says
The K-10 is an amazing tool, super fast and accurate by itself, even better in color measuring when you profile first with a spectro. But like all technologies, when you think you have the fastest meter comes Luhr Jensing with an upgrade that makes it 3x faster and sensitive! So i’m thinking about doing the upgrade, which btw is $500. Ouch. If there is a meter you want to invest in, you cannot go wrong with Klein, make sure to buy the K-10A, which already has the new sensors.
Helder Carvalho says
So, what do you suggest we (those who can’t hire a calibrator because there aren’t none available) do to get a natural skin tone? Using DNice’s slides and adjusting the contrast to 55, brightness to +5 and colour to 35 I get this http://farm4.staticflickr.com/3712/12915329003_38c2f3ef82_c.jpg in the photo looks better that it is, it is more orange/brownish, like the actor spent too much time on a tanning bed, the blu-ray is The Dark knight, from the beggining part.
Chris Heinonen says
If you look at all the charts you’ll see that using DNice’s settings, both Ray and I have higher error levels in skin tones than when using the THX Cinema modes. Have you tried using the standard THX modes and seeing if you still have the same issues? If everyone still looks too sunburnt you could use the ISFccc modes and try to reduce the Color setting a click or two and see if that helps as well. I can’t tell you how accurate it is, but if you just care to go by your eye, I’d test that as well.